In the history of foreign aid, it looked pretty harmless: a young Florida businessman decided to collect a million shirts and send them to poor people in Africa. Jason Sadler just wanted to help. He thought he'd start with all the leftover T-shirts from his advertising company, I Wear Your Shirt. But judging by the response Sadler got from a group of foreign aid bloggers, you'd think he wanted to toss squirrels into wood chippers or steal lunch boxes from fourth-graders.

"I have thick skin, I don't mind, but it's just the way they responded  it was just, 'You're an idiot, here's another stupid idea, I hope this fails,' " Sadler, 27, tells TIME. "It really was offensive because all I'm trying to do is trying to make something good happen and motivate people to get off their butts, get off the couch and do something to help." (See TIME's photo-essay "Commerce Comes to the Aid of Haiti.")

Little did Sadler know he had stumbled into a debate that is raging in the aid world about the best and worst ways to deliver charity, or whether to give at all. He crashed up against a rather simple theory that returned to prominence after aid failures following the 2004 Asian tsunami and 2010 Haiti earthquake: wanting to do something to help is no excuse for not knowing the consequences of what you're doing. (See a brief history of "We Are the World" and other music for charity.)

Sadler has never visited Africa or worked on a foreign aid project. To his critics, his pitch seemed naive with its exhortation, "Share the wealth, share your shirts  we're going to change the world." Millions of Africans who have no trouble getting shirts, and who never asked Sadler for a handout, might object to the idea that giving them more clothes will change the world. Stung from watching people donate old, useless stuff after the tsunami and earthquake, aid workers bristled. "I'm sorry to be so unkind to someone who has good intentions, but you don't get a get-home-free card just for having good intentions. You have to do things that make sense," says William Easterly, an author and New York University economics professor who is a leading critic of bad aid. "If a surgeon is about to operate on me, I'm not all that interested in whether he has good intentions. I hope he doesn't have evil intentions, but I'm much more interested in whether he knows what he's doing. People have a double standard about aid."

But why gang up on a guy who just wants to help clothe people in Africa? First, because it's not that hard to get shirts in Africa. Flooding the market with free goods could bankrupt the people who already sell them. Donating clothing is a sensitive topic in Africa because many countries' textile industries collapsed under the weight of secondhand-clothing imports that were introduced in the 1970s and '80s. "First you have destroyed these villages' ability to be industrious and produce cotton products, and then you're saying, 'Can I give you a T-shirt?' and celebrating about it?" says James Shikwati, director of the Nairobi-based Inter Region Economic Network, a think tank. "It's really like offering poison coated with sugar." (See a video of the Haitian schools supported by Ben Stiller.)

People looking to help the poor often think so-called goods-in-kind donations are a way to help, Easterly says. They're certainly an easy way to inspire potential donors. There was the boy in Grand Rapids, Mich., who collected 10,000 teddy bears for Haiti's earthquake victims. Soles4Souls.com is sending shoes. The list goes on: old soap from hotel rooms, underwear, baby formula, even Spam (the pork product, not junk e-mail). "Years  decades  of calm, reasoned discussion do not seem to have worked," an aid worker who blogs under the name Tales from the Hood told TIME by e-mail. "People are still collecting shoes, socks, underwear ... T-shirts ... somehow under the delusion that it is helpful. Sometimes loud shouting down is the only thing that gets heard." Then there's the matter of cost. Money spent shipping teddy bears to kids might be better spent providing for more pressing needs. The same goes for T-shirts.

Sadler says he never planned to dump a million shirts on the market at once. With his two partners, HELP International and WaterIsLife.com, he wanted to send a few thousand shirts at a time to orphanages in Kenya and Uganda that asked for them. Widows would sell the shirts and make a little money. "We're looking at bringing in several thousand shirts and it being a yearlong process of distribution," says Ken Surritte, founder of WaterIsLife.com. "The goal is not to hurt the economy in these areas but to be an asset and to be a blessing to these people that otherwise wouldn't have jobs."

Sadler has proven flexible: he says he is listening to his critics and no longer plans to send the shirts to Africa. He says he will find another way to use the T-shirts he collects, possibly for disaster relief, giving them to homeless shelters or using them to create other goods. He says any profits would then "go back to the company's goal of helping foster sustainability." And judging by the response on the Web, he's getting a lot of donations. "I've since listened to a lot of these people," he says. "I want to change this thing into something that's better, that's more helpful and that listens to the people that have the experience that I don't have."

There are some critics who argue that all foreign aid  whether from individuals or nonprofits or governments  is keeping Africa back. A vast body of research shows that foreign aid has done little to spur economic growth in Africa  and may have actually slowed it down. "The long-term solution is not aid. It may seem cruel that aid should stop, but really it should," says Rasna Warah, a Kenyan newspaper columnist and editor of the anthology Missionaries, Mercenaries and Misfits, a call to arms against aid. "Africa is the greatest dumping ground on the planet. Everything is dumped here. The sad part is that African governments don't say no  in fact, they say, 'Please send us more.' They're abdicating responsibility for their own citizens."